It's time to pooper-scoop your leftover medicine. Mixing cough syrup, Vicodin or Lipitor with cat litter is the new advice in the United States on getting rid of unused, and potentially dangerous, medications. Preferably used cat litter.

It's a compromise, better for the environment than flushing — and one that ensures dangerous medicines aren't stumbled upon by children, pets or drug abusers.

Health Canada advises people not to put out-of-date or unused medication in the garbage or down the toilet or sink.
(AP)

In Canada, Health Canada tells people not to throw medications into the garbage or toilet, and individual municipalities have their own rules about what can and can't go into landfill sites. Usually, people are urged to take unused medicines back to pharmacies for proper disposal.

But in the U.S., a government experiment is about to send the kitty litter advice straight to thousands of patients who use potent painkillers, sleeping pills and other controlled substances.

Prescription drug abuse is on the rise, and research suggests more than half of people who misuse those drugs get them for free from a friend or relative. In other words, having leftovers in the medicine cabinet is a risky idea. Anyone visiting your house could steal them.

For that reason, 6,300 pharmacies around the United States have signed up for a pilot project with the Substance Abuse and Mental Health Services Administration (SAMHSA). When patients fill prescriptions for a list of abuse-prone medicines, from Ambien to Vicodin, the pharmacist also will hand over a flyer urging them to take the cat-litter step if they don't wind up using all their pills.

Old coffee grounds work as well, or doggie doo, and even sawdust.

"We don't want to assert that this is a panacea for the larger problem," says SAMHSA's Dr. H. Westley Clark. "It just provides them with a caveat that these are not things you can just lay around."

But the concern isn't only about controlled substances. How to best dispose of any medicine, whether prescription or over-the-counter, is a growing issue. Unfortunately, "we don't have a silver bullet," says Joe Starinchak of the U.S. Fish and Wildlife Service.

No one knows just how many unused drugs North Americans dump each year, or how many are hoarded because patients simply don't know what to do with them or that they should dispose of them.

Once, patients were told to flush old drugs down the toilet. No more – do not flush unless you have one of the few prescriptions that the U.S. Food and Drug Administration specifically labels for flushing.

That's because antibiotics, hormones and other drugs are being found in waterways, raising worrisome questions about potential health and environmental effects. Already, studies have linked hormone exposure to fish abnormalities. Germs exposed to antibiotics in the environment may become more drug-resistant.

Some communities set aside "take-back" days to return leftover doses to pharmacies or other collection sites for hazardous-waste incineration. The Environmental Protection Agency recently funded a novel pilot program by the University of Maine to see if consumers would mail back unused drugs — a program that local officials estimate could cull up to 1.5 tonnes of medications.

But it's not clear if incineration is better for the environment than the slow seepage from a landfill, cautions the Fish and Wildlife Service's Starinchak.

Take-back programs also require legal oversight to make sure what's collected isn't then diverted for illegal use.

Larger dispoal program planned

Next year, Fish and Wildlife will team with the American Pharmacists Association for a larger campaign called SMARxT Disposal. The campaign will spread this latest advice through even more drugstores, to purchasers of all types of medicine.

"There is a $64,000 question here: Whether people really will get rid of it," says Carol Boyd, director of the University of Michigan's Institute for Research on Women and Gender and a well-known specialist on drug diversion.

Say you're prescribed a week's worth of Vicodin for pain after a car crash, and you use only three days' worth. Most people would keep the rest, to avoid paying for more if they suffer serious pain for some other reason later. Boyd isn't sure how to counter that money issue.

But keeping the leftovers makes them accessible for misuse by children, other relatives or visitors. Stealing aside, Boyd's research uncovered that friends and family openly share these pills – "Use this, it helped me" – even with teens and college students, apparently not realizing there could be serious health consequences.

"The public needs to know this," Boyd says of the disposal advice. "What's not easy is, we don't know if it's working."

Health Canada advises the following in properly disposing of drugs:

• Do not put out-of-date or unused medication in the garbage or down the toilet or sink.
• Check to see if your pharmacy has a program that disposes of unused or expired drugs in an environmentally safe manner. Most pharmacies do and programs exist in B.C., Alberta and many parts of other provinces and territories to incinerate unused drugs.
• If your area does not have such a program, see if your municipality incinerates drugs. If so, take your unused drugs to your municipality's waste disposal depot.

With files from the Canadian Press